JPH0854746A - Electrophotographic photoreceptor - Google Patents

Abstract

PURPOSE:To obtain a photoreceptor excellent in memory function and capable of forming many copies from the same original. CONSTITUTION:This electrophotographic photoreceptor contains a thioketone compd. represented by formula I and a positive hole transferring arylamine compd. contg. one or more triarylamine structures represented by formula II in one molecule in the photoconductive layer. In the formula I, each of Ar1 and Ar2 is an arom. hydrocarbon group or an arom. heterocyclic group. In the formula II, each of A, B and C is an arom. hydrocarbon group or an arom. heterocyclic group and A and B may bond to each other to form a hetero ring.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic photoreceptor. Especially, it relates to an electrophotographic photoreceptor having a memory function.

[0002]

2. Description of the Related Art An electrophotographic image forming method has been put to practical use in many fields. Particularly, in the field of copiers / printers, it is widely used as a plain paper copier and an electrophotographic printer using a light source such as an LED array or a laser diode. As the copying process, the Carlson method is generally used, and a method of repeating the steps of charging a photoconductor, forming an electrostatic latent image by image exposure, developing toner, transferring to paper, and cleaning the photoconductor is adopted. There is. Even when making multiple copies from the same original, the above steps are repeated, but the photoconductor has a memory function to hold the electrostatic latent image for a certain period of time, and the image exposure step is omitted. Then, an electrostatic printing method in which a large number of sheets are copied by repeating the steps of charging, developing, transferring, and cleaning is of interest in terms of shortening the copying time.

This requires a large number of copies to be processed by ordinary copying, but does not require a company specializing in printing to print several hundred to several thousand copies, that is, a so-called gray area demand. It is a highly anticipated item. Aiming to apply to such applications,
Research on a photoconductor having a memory function has been conducted for some time.

As an example thereof, conventionally, a photoreceptor (Tappi 56, 1) in which ortho-dinitrobenzene and trichloroacetic acid were added to a polyvinylcarbazole (PVK) layer was used.
29, 1973), polyvinylcarbazole and 2,
A photoreceptor obtained by adding a leuco body of a triphenylmethane dye to a photosensitive layer made of 4,7-trinitrofluorenone (TNF) (Journal of the Photographic Society of Japan, 44, 104, 1981).
Year), a photoconductor (Photographic Science and
Engineering, 26, 69, 1982.
Year) is known.

A system in which a switching layer containing copper-TCNQ (tetracyanoquinodimethane) complex microcrystals is laminated on a photosensitive layer made of PVK-TeNF (tetranitrofluorenone) complex (Electrophotographic Society, 24 , 86). page,
(1985) or a system in which a layer made of a conductive polymer such as polyaniline or polypyrrole by electrolytic polymerization is laminated on a photosensitive layer made of PVK or PVK-TNF complex (Ja
panese Journal of Applied
Physics, 28, 1396 and 2517.
Page, 1989) and the like are also known. All of these photoconductors exhibit a phenomenon in which their chargeability is lowered when irradiated with strong light, that is, a so-called charge-accepting photomemory effect.

[0006]

However, these photoconductors have an insufficient memory holding ability, cannot copy a large number of sheets, and have a large decrease in memory function due to repeated use of the photoconductor. It has various problems such as the short life of the photoconductor. Furthermore, some of these photoconductors have the charging / light-attenuating characteristics required in the usual Carlson process in addition to the memory function, but some of them have a memory function. As a result, there is a serious problem that the charging / light attenuation characteristics are lowered.

[0007]

In view of the above points, the present inventors have made earnest studies on an electrophotographic photoreceptor having an excellent memory function capable of copying a large number of sheets from the same original document, and as a result, have been identified. The inventors have found that a photoreceptor containing the thioketone-based compound and the specific arylamine-based compound exhibits extremely excellent performance, and arrived at the present invention. That is, the gist of the present invention is to provide an electrophotographic photoreceptor having at least a photoconductive layer on a conductive substrate, wherein the photoconductive layer contains a thioketone compound represented by the general formula (1) )

[0008]

[Chemical 4]

(Wherein Ar ₁ and Ar ₂ each represent an aromatic hydrocarbon group which may have a substituent or an aromatic heterocyclic group which may have a substituent) and , A triarylamine structure represented by the following general formula (2) in the molecule, general formula (2)

[0010]

[Chemical 5]

(In the formula, A, B and C each represent an aromatic hydrocarbon group which may have a substituent or an aromatic heterocyclic group which may have a substituent, and A and B are Which may form one heterocycle in combination with each other.) In the molecule, contains a hole-transporting arylamine compound. .

The present invention will be described in detail below. As the conductive substrate of the present invention, any known conductive substrate used for electrophotographic photoreceptors can be used. For example, a drum or sheet made of a metal material such as aluminum, stainless steel, copper or nickel or a laminate of foils of these metals; or a metal such as aluminum, copper or palladium or a metal oxide such as indium oxide or indium oxide; Insulating substrate such as plastic film, paper, plastic drum, paper tube, glass tube, etc., whose surface has been subjected to conductive treatment by vapor deposition of carbon black, copper iodide, polymer electrolyte or the like, or by coating with a suitable binder or the like; Alternatively, a plastic drum or sheet made conductive by containing a conductive substance such as metal powder, carbon black or carbon fiber can be used. Among these, the metal drum and the metal such as aluminum on the surface,
A plastic film that has been electrically conductively treated with a metal oxide or the like is desirable.

Between the conductive substrate and the photoconductive layer, a known barrier layer or intermediate layer which is commonly used may be provided. Examples thereof include inorganic layers such as aluminum anodized film, aluminum oxide and aluminum hydroxide; organic layers such as polyvinyl alcohol, casein, polyvinylpyrrolidone, polyacrylic acid, celluloses, gelatin, starch, polyurethane, polyimide and polyamide. Or, there may be mentioned one in which fine particles of a metal oxide such as alumina and titania are dispersed in the organic layer mentioned here.

Next, the photoconductive layer will be described. The photoconductive layer may be formed by stacking a charge generating layer and a charge transporting layer in this order, reversely stacking them, or a so-called dispersion type in which charge generating material particles are dispersed in a charge transporting medium. Further, it may be composed of only the charge transport layer. If the final charge transport layer is a single layer, the coating is 1
There is an advantage that it can be manufactured at low cost only once. On the other hand, in the case of a photoconductor having a photoconductive layer containing another charge generation layer or charge generation substance particles, there is an advantage that it can be used in a usual Carlson process in addition to a memory function. The thioketone compound of the general formula (1) of the present invention may be contained in any part of the photoconductive layer.

In the case of the laminated photoconductive layer, the charge generating substance used in the charge generating layer includes selenium and its alloys, arsenic-selenium, cadmium sulfide, zinc oxide, other inorganic photoconductive substances, phthalocyanines, azo dyes, Various organic photoconductive substances such as quinacridone, polycyclic quinone, pyrylium salt, thiapyrylium salt, indigo, thioindigo, anthanthrone, pyrrolopyrrole, pyranthrone and cyanine can be used. Among them, metal-free phthalocyanine, copper indium chloride, gallium chloride, tin, oxytitanium, zinc, vanadium, or other metals or oxides thereof, phthalocyanines coordinated with chlorides, monoazo, bisazo, trisazo, azo such as polyazo Pigments are preferred.

The charge generation layer comprises fine particles of these substances, such as polyester resin, polyvinyl acetate, polyacrylic acid ester, polymethacrylic acid ester, polycarbonate, polyvinyl acetoacetal, polyvinyl propional, polyvinyl butyral, phenoxy resin, epoxy resin, You may use it in the dispersion layer of the form bound by various binder resins, such as urethane resin, cellulose ester, and cellulose ether. The usage ratio in this case is usually 30 with respect to 100 parts by weight of the binder resin.
To 500 parts by weight, and its film thickness is usually 0.1 μm to 2 μm, preferably 0.15 μm to 0.8 μm. Further, the charge generation layer may contain various additives such as a leveling agent, an antioxidant and a sensitizer for improving the coating property, if necessary. The charge generation layer may be a vapor deposition film of the above charge generation substance.

The charge transport layer of the single-layer or multi-layer type photoreceptor of the present invention is basically composed of a hole transport property, an arylamine compound and a binder polymer. When the thioketone compound of the present invention is not added to the charge generation layer, the thioketone compound is added to the charge transport layer. Further, if necessary, various additives such as an antioxidant, a sensitizer, a plasticizer, an ultraviolet absorber and a leveling agent may be contained. The thickness of the charge transport layer is usually 5 to 60.
The thickness is preferably μm, preferably 8 to 40 μm.

Next, the binder polymer of the charge transport layer will be described. As the binder polymer, a polymer that has good compatibility with each compound that constitutes this layer, especially a hole-transporting arylamine compound, and that does not adversely affect the movement of charge carriers in the layer is preferable. . For example, styrene, vinyl acetate, vinyl chloride, acrylic acid ester, methacrylic acid ester, polymers and copolymers of vinyl compounds such as butadiene, polyvinyl acetal, polycarbonate, polyester,
Examples thereof include polysulfone, polyphenylene oxide, polyurethane, cellulose ester, cellulose ether, alkyd resin, phenoxy resin, silicon resin and epoxy resin. Among these, polyester resins, polycarbonate resins, methacrylic resins, acrylic resins and phenoxy resins are preferable, and polycarbonate resins and methacrylic resins are particularly preferable. The amount of the binder polymer used is usually in the range of 0.1 to 30 times by weight, preferably 0.3 to 10 times by weight, of the hole transporting arylamine compound described below.

In the case of the dispersion type photoconductive layer, a binder resin and a hole-transporting arylamine compound having the same compounding ratio as those of the above charge transport layer are used as main components, and a thioketone compound is added to the matrix. The above-mentioned charge generating substance is dispersed. In that case, it is necessary that the particle size of the charge generating substance is sufficiently small, and the particle size is preferably 1 μm or less, more preferably 0.5 μm or less. If the amount of the charge generating substance dispersed in the photosensitive layer is too small, sufficient sensitivity cannot be obtained, and if the amount is too large, there are adverse effects such as a decrease in charging property and a decrease in sensitivity. For example, preferably 0.5 to 50% by weight. In the range of
It is more preferably used in the range of 1 to 20% by weight. The thickness of the photosensitive layer is usually 5 to 50 μm, more preferably 1
Used at 0-45 μm. Also in this case, the film forming property,
Known plasticizers for improving flexibility, mechanical strength, etc., additives for suppressing residual potential Dispersion aids for improving dispersion stability, leveling agents for improving coating properties, surface activity Agents such as silicone oil, fluorinated oil and other additives may be added.

An overcoat layer composed mainly of a conventionally known thermoplastic or thermosetting polymer may be provided as the outermost surface layer on the photoconductive layer. As a method for forming each layer, a known method such as sequentially applying a coating solution obtained by dissolving or dispersing a substance contained in the layer in a solvent can be applied.

The thioketone compound used in the present invention is added to the photoconductive layer in an amount of 0.001 to 20% by weight, preferably 0.02 to 5% by weight. In the case of a two-layer system, it may be added to either the charge transport layer or the charge generation layer, but it is preferably used by adding it to the charge transport layer. This compound plays a role of imparting a memory function in the photoreceptor of the present invention. As the thioketone compound, the compound represented by the general formula (1) is used. In the formula, Ar ₁ and Ar _{2 each} represent a divalent group derived from an aromatic hydrocarbon group or a divalent group derived from an aromatic heterocycle, both of which have a substituent. Good. Ar ₁ and Ar ₂ may be the same or different.

Examples of aromatic hydrocarbons include benzene, naphthalene, anthracene, pyrene, phenanthrene, acenaphthene, biphenyl and fluorene.
Examples of the aromatic heterocycle include pyrrole, pyridine, thiophene, furan, carbazole, quinoline, acridine, phenothiazine and the like.

Substituents which may be contained in Ar ₁ and Ar ₂ include an alkyl group (preferably a C ₁ -C ₆ alkyl group such as a methyl group and an ethyl group); an alkoxy group (preferably a methoxy group, alkoxy C ₁ -C _6, such as ethoxy groups); a phenoxy group; an amino group; arylalkoxy groups such as benzyloxy group; an alkylthio group such as methylthio group; naphthoxy aryloxy group such as a group methylamino group, dimethylamino Group, diethylamino group,
Examples thereof include mono- or di-substituted amino groups such as diphenylamino group; aryl vinyl groups; halogen atoms such as chlorine atom and bromine atom. Examples of preferable thioketone compounds are shown below (Exemplified compound 1) (Thioketone compounds)

[0024]

[Chemical 6]

As the thioketone compound, a single compound may be added, or some compounds may be appropriately mixed and used. Among known additives that impart a memory function, the addition of the additive may be useful for developing the memory function, but may significantly impair the photoconductive property or light attenuation property originally possessed by the photoconductive layer. . For example, increase in residual potential, decrease in sensitivity, decrease in carrier moving speed, etc. As one of such examples, for example, polyvinylcarbazole-
It is known that the sensitivity (light decay rate) is significantly reduced when leucomalachite green is added to the trinitrofluorenone photoconductive layer. (Photoqr.Sc
i. Enq. 25 p35 (1981)

On the other hand, in the case of adding the thioketone compound of the present invention, as will be shown later in Examples,
It has excellent characteristics that it does not adversely affect the light attenuation characteristics or that the light attenuation characteristics are improved in some cases. The hole transporting arylamine compound used in the present invention will be described below.

The hole transporting compound acts as a carrier for transporting holes which are charge carriers. The hole transport phenomenon can be regarded as an electron transfer between molecules or a redox reaction, and an electron donating compound having a small ionization potential is suitable for effective hole transport. Aryl amine compounds are typical compounds having such properties. The hole transporting arylamine compound in the present invention contains one or a plurality of triarylamine structures represented by the general formula (2). That is,
A compound having this triazole amine structure or a plurality of, for example, 2 to 5 or so triarylamine structures (which may be the same or different) are directly or appropriately (for example, 2 to 5 valent) organic compounds. They are bound via a sex-bonding group.

Next, A, B and C in the general formula (2) will be described. As the aromatic hydrocarbon group, a phenyl group;
Naphthyl group; or a group derived from anthracene, pyrene, phenanthrene, acenaphthene, biphenyl and the like. Examples of the aromatic heterocycle include groups derived from pyrrole, pyridine, thiophene, furan, carbazole, quinoline, acridine, phenothiazine and the like. Examples of the substituent which may be contained in A, B or C include an alkyl group such as a methyl group and an ethyl group; an alkoxy group such as a methoxy group and an ethoxy group; a phenoxy group;
Aryloxy group such as naphthoxy group; Alkylthio group such as methylthio group; Arylalkoxy group such as benzyloxy group; Amino group; Mono- or di-substituted amino such as methylamino group, dimethylamino group, diphenylamino group and dibenzylamino group Group; an aryl-substituted vinyl group such as a 2-phenylvinyl group; and a diaryl-substituted vinyl group such as a 2,2-diphenylvinyl group.
When an aryl group such as a phenyl group is contained in these substituents, it may further contain a substituent such as the above-mentioned alkyl group or alkoxy group.

Also, regarding A and B, they are united with each other,
You may form one heterocycle as a whole. An example of such a case is a case where two benzene rings are bonded to each other to form a carbazole ring with a central nitrogen atom. The binding group for binding a plurality of triarylamine structures may be any divalent or higher valent organic binding group, and one example thereof is

[0030]

[Chemical 7]

Alternatively, there may be mentioned a bonding group in which some selected from these are bonded to each other. In the arylamine-based compound of the present invention, any number of triarylamine structures may be contained, but it is particularly preferable that the number of triarylamine structures is two as shown in the following general formula (3). This is because a compound containing only one triarylamine structure has a sublimation property and is liable to cause problems such as reduction from the photoconductive layer, and in some cases properties such as mobility are insufficient. This is because when the number is 3 or more, problems in production such as compound synthesis and purification, and solubility and compatibility with a solvent or a binder are likely to occur. (General formula [3])

[0032]

Embedded image

(In the formula, Ar₃And Ar₆Are each
Aromatic hydrocarbon group or substituent which may contain a substituent
Represents an aromatic heterocyclic group which may contain_FourAnd
And Ar _FiveIs a divalent aromatic carbon which may contain a substituent
Divalent aromatic heterocycle optionally containing hydrogen group or substituent
Represents a group. D and E are each optionally substituted.
Represents an aromatic heterocyclic group, Ar₃And D or Ar₆And E
They may combine with each other to form one heterocycle. X is
It represents a divalent linking group. ) Some of the specific examples of the arylamine compounds of the present invention are shown below.
Shown in. In addition, specific examples of desirable compounds are described in Japanese Patent Application No.
Included in the exemplified compounds of 4-110248
It (Exemplified Compound 2) Arylamine compound

[0034]

[Chemical 9]

[0035]

INDUSTRIAL APPLICABILITY The electrophotographic photosensitive member according to the present invention in which the photoconductive layer contains a specific thioketone compound has a very stable memory function, and is particularly used as a master for electrostatic printing. Suitable for Furthermore, when the photoconductive layer contains a charge generating substance, it also possesses the charging light attenuation performance necessary for the usual Carlson process, and for example, when one photoconductor is used for normal copying, It can support two operations of printing multiple sheets by the memory function. Further, it is also possible to apply to a composite type image forming process in which both these functions are combined. Further, in the case of containing a charge generating substance having a sensitivity in a long wavelength region, it also has an effect of improving sensitivity, that is, a sensitizing effect, of the charging light attenuation characteristics.

[0036]

EXAMPLES The present invention will be described in more detail with reference to examples below, but the present invention is not limited thereto. Example-1 10 parts by weight of a bisazo compound having the following structure was added to 150 parts by weight of 4-methoxy-4-methylpentanone-2, and pulverized and dispersed by a sand grind mill. The pigment dispersion obtained here was added to a 5% 1,2-dimethoxyethane solution of polyvinyl butyral to finally prepare a dispersion having a solid content concentration of 4.0%. The dispersion thus obtained is applied to the surface of a polyethylene terephthalate film on which aluminum is vapor-deposited using a wire bar, and a charge generation layer is provided so that the dry film thickness is 0.4 g / m ^2. It was

[0037]

[Chemical 10]

Next, with respect to 100 parts by weight of bisphenol-A-polycarbonate, 80 parts by weight of Exemplified compound (2-1) and 0.2 parts by weight of Exemplified compound (1-1) are added 1,4.
-The solution obtained by dissolving in dioxane is applied on the above charge generation layer using an applicator, and then 40
Min, dried at 125 ° C for 20 minutes, and the film thickness after drying is 13
A μm charge transport layer was provided.

The two-layer type photoconductor (A) thus prepared was used as a photoconductor characteristic measuring device [E, manufactured by Kawaguchi Electric Co., Ltd., E
The PA-8100 (hereinafter referred to as "EPA") is mounted and charged / attenuated by negative corona discharge and white light irradiation (exposure amount required until the charged voltages V _O and V _O after corona discharge fall to half). The half-exposure amount E _1/2 ) was measured in the static mode. What is EPA's study mode?
In this mode, after charging by corona discharge, the surface potential of the photoreceptor sample is measured in the dark or at the time of light irradiation with the photoreceptor sample being stopped in front of the transparent electrode of the surface electrometer. The results of measuring the characteristics of the photoconductor (A) by this method are shown in Table 1. In the table, the results for the photoconductor (XA) prepared in the same manner except that the exemplified compound (1) was not added are shown as comparative examples. From these results, it can be seen that the photoconductor (A) has good charging and light attenuation characteristics as the photoconductor (XA) of the comparative example. That is, the properties required for the usual Carlson process are not affected by the addition of the thioketone compound of the present invention.

[0040]

[Table 1] Table-1 Charging / light decay characteristics (negative charging, white light) Photoreceptor additive V _o (-v) E _1/2 (lux · sec) (A) Exemplified compound (1) 776 1.29 (XA) None 734 1.23

Next, the memory function (charge-accepting optical memory effect) of this photoreceptor (A) was evaluated. For this evaluation, the saturation electrification voltage was measured by the dynamic mode of EPA. 1000r in this mode
By setting the photoconductor sample on a turntable rotating at pm and passing the charging device by corona discharge and the front of the electrode of the surface electrometer alternately at high speed, the transition of the surface potential during charging by corona discharge, It is possible to measure the saturation electrification voltage after charging for a certain period of time. The charging characteristic of the photoconductor can be measured by such a dynamic mode or the static mode used for the evaluation of the light attenuation characteristic.

In the evaluation of the charging property of the photoconductor of the comparative example described below, the potential change is large in the measurement in the static mode, it is difficult to obtain reliable data on the charging property for comparison, and the stability is sufficiently stable in the dynamic mode. There was no choice but to measure the saturated electrification voltage. Therefore, the same dynamic mode is used for measuring the charging property of the photoconductor (A).

When a negative corona charge was applied to the photoconductor (A) in the dynamic mode for 30 seconds.
As shown in the curve (a) of FIG.
It was 6V. After performing total exposure for 30 minutes with a white fluorescent lamp (illuminance: 5,000 lux), Vs was measured again, and as shown by the curve (b) in FIG. 1, it was -403 V (42% of the initial value). It was shown that this photoreceptor (A) has a large charge-accepting photomemory effect. Furthermore, after this, the stability of the memory effect was investigated by performing the same measurement at a certain time. Curves (c) and (d) in FIG. 1 are the results after standing for 65 minutes and 6 hours, respectively, and the memory effect of the photoconductor of the present invention is very stable,
It can be seen that a sufficient chargeable contrast can be maintained even after 6 hours. In FIG. 2, the transition of Vs with respect to the standing time is shown with the horizontal axis representing time and the vertical axis representing saturation charge voltage. This result is
It is shown that the photosensitive member of the present invention is excellent in stability of the memory function required for the master for electrostatic printing, as compared with the photosensitive member (XB) of the comparative example shown below. Further, when this photoconductor was subjected to heat treatment in an oven at 100 ° C. for 3 minutes, the chargeability of the photoconductor returned to an almost initial state.
(FIG. 1 curve (e)) That is, the memory function can be erased by heat.

Comparative Example-1 PVK (polyvinylcarbazole) -TNF (2,4,7-trinitrofluorenone), which is widely known as a photoreceptor showing a charge-accepting memory effect for comparison with the photoreceptor of the present invention. A single-layer photosensitive body made of LMG (leucomalachite green) was prepared. 100 parts by weight of PVK,
91 parts by weight of TNF and 20 parts by weight of LMG were dissolved in THF and coated on an aluminum vapor-deposited polyester film to prepare a photoreceptor (XC) having a film thickness of 15 μm. It is known that this system exhibits a memory effect at the time of positive charging. Therefore, by using positive corona charging, the saturation electrification voltage in the same dynamic mode as in the above-mentioned example was measured, and the memory effect of this system was measured. The stability of was investigated. As shown in Figure-3,
The memory effect of the photoconductor (XC) of this comparative example is very unstable and the recovery is fast.

Example-2 In place of the bisazo pigment of Example-1, a titanyl phthalocyanine pigment is used, and a two-layer type photoreceptor (B) is prepared by the same procedure.
It was created. Further, a photoconductor (XB) containing no exemplified compound (3) was prepared in the same procedure as that of the photoconductor. Table 2 shows these charging / light attenuation characteristics. It should be noted that monochromatic light of 780 nm was used as a light source when measuring the light attenuation characteristics. From the results shown in the table, the photoconductor containing the thioketone compound shows good chargeability and higher sensitivity (small E _1/2 value) than the photoconductor without addition. Thus, it can be seen that the thioketone-based compound not only impairs the performance required for the usual Carlson process, but rather improves it.

[0046]

[Table 2] Table-2 Charging / light decay characteristics (negative charging, 780 nm) Photoreceptor additive V _o (-v) E _1/2 (μJ / cm ² ) (B) Exemplified compound (1) 717 0.32 (XB) None 691 0.35

Next, the memory function of this photoconductor (B) was examined. Before and after irradiation with a fluorescent lamp of 5000 lux (5 minutes), static voltage was measured in static mode. As a result, it was found that the static voltage decreased to 39% of the initial value and that it had a good memory function.

Example 3 An image exposure is carried out by superimposing a transparent original on the sheet-shaped photoconductor (A) prepared in Example-1 and irradiating it with a fluorescent lamp.
An image memory was formed on the photoreceptor. This photoreceptor was wound around an aluminum drum, mounted on a commercially available copying machine, and the steps of charging, developing, transferring, fixing, cleaning, and neutralizing were repeated, and several hundred good images were obtained. That is, it was confirmed that the photoreceptor of the present invention has excellent performance as a master for electrostatic printing.

[Brief description of drawings]

FIG. 1 is a graph showing a charging curve of a photoconductor A of Example 1.

FIG. 2 is a graph showing a transition of Vs of the photoconductor (A) in Example 1 with respect to a standing time.

FIG. 3 is a graph showing a transition of Vs of a photoconductor (XC) with respect to a standing time in Comparative Example 1.

Claims (2)

[Claims] 1. A photoconductor for electrophotography having at least a photoconductive layer on a conductive substrate, wherein a thioketone compound represented by the following general formula [1] is contained in the photoconductive layer (general formula [1]). [Chemical 1] (In the formula, Ar ₁ and Ar ₂ each represent an aromatic hydrocarbon group which may have a substituent or an aromatic heterocyclic group which may have a substituent.) And the following general An electrophotographic photoreceptor comprising a hole-transporting arylamine compound containing one or more triarylamine structures represented by formula (2) in the molecule. (General formula [2]) (In the formula, each of A, B and C represents an aromatic hydrocarbon group which may have a substituent or an aromatic heterocyclic group which may have a substituent, and A and B are combined. May form one heterocycle as a whole.) 2. A hole-transporting aryla according to claim 1.
The min-based compound is a compound represented by the following general formula [3]
An electrophotographic photosensitive member characterized by being present. (General formula [3])(In the formula, Ar₃And Ar₆Each include a substituent
Optionally containing aromatic hydrocarbon groups or substituents
Represents a good aromatic heterocyclic group, Ar_FourAnd Ar _FiveIs
A divalent aromatic hydrocarbon group which may contain a substituent, or
Represents a divalent aromatic heterocyclic group which may have a substituent.
You D and E are aromatic carbons optionally containing substituents
Aromatic heterocycles that may contain hydrogen fluoride groups or substituents
Represents a ring group, Ar₃And D or Ar₆And E united
Each may form one heterocycle. X is a bivalent bond
Represents a group. )